1 files changed, 80 insertions, 0 deletions
diff --git a/test/syscalls/linux/socket_ipv6_udp_unbound.cc b/test/syscalls/linux/socket_ipv6_udp_unbound.cc
index 612fd531c..c431bf771 100644
--- a/test/syscalls/linux/socket_ipv6_udp_unbound.cc
+++ b/test/syscalls/linux/socket_ipv6_udp_unbound.cc
@@ -39,6 +39,86 @@
 namespace gvisor {
 namespace testing {
 
+using ::testing::IsNull;
+using ::testing::NotNull;
+
+TEST_P(IPv6UDPUnboundSocketTest, IPv6PacketInfo) {
+  auto sender_socket = ASSERT_NO_ERRNO_AND_VALUE(NewSocket());
+  auto receiver_socket = ASSERT_NO_ERRNO_AND_VALUE(NewSocket());
+
+  auto sender_addr = V6Loopback();
+  ASSERT_THAT(bind(sender_socket->get(), AsSockAddr(&sender_addr.addr),
+                   sender_addr.addr_len),
+              SyscallSucceeds());
+
+  auto receiver_addr = V6Loopback();
+  ASSERT_THAT(bind(receiver_socket->get(), AsSockAddr(&receiver_addr.addr),
+                   receiver_addr.addr_len),
+              SyscallSucceeds());
+  socklen_t receiver_addr_len = receiver_addr.addr_len;
+  ASSERT_THAT(getsockname(receiver_socket->get(),
+                          AsSockAddr(&receiver_addr.addr), &receiver_addr_len),
+              SyscallSucceeds());
+  ASSERT_EQ(receiver_addr_len, receiver_addr.addr_len);
+
+  // Make sure we get IPv6 packet information as control messages.
+  constexpr int one = 1;
+  ASSERT_THAT(setsockopt(receiver_socket->get(), IPPROTO_IPV6, IPV6_RECVPKTINFO,
+                         &one, sizeof(one)),
+              SyscallSucceeds());
+
+  // Send a packet - we don't care about the packet itself, only the returned
+  // IPV6_PKTINFO control message.
+  char send_buf[200];
+  RandomizeBuffer(send_buf, sizeof(send_buf));
+  ASSERT_THAT(RetryEINTR(sendto)(
+                  sender_socket->get(), send_buf, sizeof(send_buf), 0,
+                  AsSockAddr(&receiver_addr.addr), receiver_addr.addr_len),
+              SyscallSucceedsWithValue(sizeof(send_buf)));
+
+  // Check that we received the packet with the packet information control
+  // message.
+  char recv_buf[sizeof(send_buf) + 1];
+  in6_pktinfo received_pktinfo;
+  char recv_cmsg_buf[CMSG_SPACE(sizeof(received_pktinfo))];
+  iovec recv_iov = {
+      .iov_base = recv_buf,
+      .iov_len = sizeof(recv_buf),
+  };
+  msghdr recv_msg = {
+      .msg_iov = &recv_iov,
+      .msg_iovlen = 1,
+      .msg_control = recv_cmsg_buf,
+      .msg_controllen = sizeof(recv_cmsg_buf),
+  };
+  ASSERT_THAT(
+      RetryEINTR(recvmsg)(receiver_socket->get(), &recv_msg, 0 /* flags */),
+      SyscallSucceedsWithValue(sizeof(send_buf)));
+  EXPECT_EQ(memcmp(send_buf, recv_buf, sizeof(send_buf)), 0);
+
+  cmsghdr* cmsg = CMSG_FIRSTHDR(&recv_msg);
+  ASSERT_THAT(cmsg, NotNull());
+  EXPECT_EQ(cmsg->cmsg_len, CMSG_LEN(sizeof(in6_pktinfo)));
+  EXPECT_EQ(cmsg->cmsg_level, IPPROTO_IPV6);
+  EXPECT_EQ(cmsg->cmsg_type, IPV6_PKTINFO);
+  // As per cmsg(3) (https://www.man7.org/linux/man-pages/man3/cmsg.3.html),
+  //
+  //   CMSG_DATA() returns a pointer to the data portion of a cmsghdr. The
+  //   pointer returned cannot be assumed to be suitably aligned for accessing
+  //   arbitrary payload data types. Applications should not cast it to a
+  //   pointer type matching the payload, but should instead use memcpy(3) to
+  //   copy data to or from a suitably declared object.
+  memcpy(&received_pktinfo, CMSG_DATA(cmsg), sizeof(received_pktinfo));
+  EXPECT_EQ(
+      memcmp(&received_pktinfo.ipi6_addr,
+             &(reinterpret_cast<sockaddr_in6*>(&sender_addr.addr)->sin6_addr),
+             sizeof(received_pktinfo.ipi6_addr)),
+      0);
+  EXPECT_EQ(received_pktinfo.ipi6_ifindex,
+            ASSERT_NO_ERRNO_AND_VALUE(GetLoopbackIndex()));
+  EXPECT_THAT(CMSG_NXTHDR(&recv_msg, cmsg), IsNull());
+}
+
 // Test that socket will receive IP_RECVORIGDSTADDR control message.
 TEST_P(IPv6UDPUnboundSocketTest, SetAndReceiveIPReceiveOrigDstAddr) {
   auto sender = ASSERT_NO_ERRNO_AND_VALUE(NewSocket());